Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1YILPk-0001d5-UI for bitcoin-development@lists.sourceforge.net; Mon, 02 Feb 2015 18:08:00 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.192.53 as permitted sender) client-ip=209.85.192.53; envelope-from=brian.erdelyi@gmail.com; helo=mail-qg0-f53.google.com; Received: from mail-qg0-f53.google.com ([209.85.192.53]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1YILPj-0000pW-Q4 for bitcoin-development@lists.sourceforge.net; Mon, 02 Feb 2015 18:08:00 +0000 Received: by mail-qg0-f53.google.com with SMTP id a108so48642699qge.12 for ; Mon, 02 Feb 2015 10:07:54 -0800 (PST) X-Received: by 10.140.30.7 with SMTP id c7mr8750403qgc.48.1422900474129; Mon, 02 Feb 2015 10:07:54 -0800 (PST) Received: from [192.168.1.126] ([64.147.83.112]) by mx.google.com with ESMTPSA id u65sm9393492qge.7.2015.02.02.10.07.53 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 02 Feb 2015 10:07:53 -0800 (PST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (1.0) From: Brian Erdelyi X-Mailer: iPad Mail (12B466) In-Reply-To: Date: Mon, 2 Feb 2015 14:07:52 -0400 Content-Transfer-Encoding: quoted-printable Message-Id: References: <27395C55-CF59-4E65-83CA-73F903272C5F@gmail.com> <54CE3816.6020505@bitwatch.co> <68C03646-02E7-43C6-9B73-E4697F3AA5FD@gmail.com> To: =?utf-8?Q?Martin_Habov=C5=A1tiak?= X-Spam-Score: -1.3 (-) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (brian.erdelyi[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.3 AWL AWL: Adjusted score from AWL reputation of From: address X-Headers-End: 1YILPj-0000pW-Q4 Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Proposal to address Bitcoin malware X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Feb 2015 18:08:01 -0000 Martin, Yes, the second signing could be done by a mobile device that I owned and co= ntrolled (I wasn't thinking that initially). I was thinking that online ser= vices are popular because of convenience and there should be a better way to= address security (privacy issues not withstanding). I think these are practical approaches and just doing a sanity check. Thank= s for the vote of confidence. Brian Erdelyi Sent from my iPad > On Feb 2, 2015, at 1:54 PM, Martin Habov=C5=A1tiak wrote: >=20 > Good idea. I think this could be even better: >=20 > instead of using third party, send partially signed TX from computer > to smartphone. In case, you are paranoid, make 3oo5 address made of > two cold storage keys, one on desktop/laptop, one on smartphone, one > using third party. > If it isn't enough, add requirement of another four keys, so you have > three desktops with different OS (Linux, Windows, Mac) and three > mobile OS (Android, iOS, Windows Phone), third party and some keys in > cold storage. Also, I forgot HW wallets, so at least Trezor and > Ledger. I believe this scheme is unpenetrable by anyone, including > NSA, FBI, CIA, NBU... >=20 > Jokes aside, I think leaving out third party is important for privacy reas= ons. >=20 > Stay safe! >=20 > 2015-02-02 18:40 GMT+01:00 Brian Erdelyi : >> Another concept... >>=20 >> It should be possible to use multisig wallets to protect against malware.= For example, a user could generate a wallet with 3 keys and require a tran= saction that has been signed by 2 of those keys. One key is placed in cold s= torage and anther sent to a third-party. >>=20 >> It is now possible to generate and sign transactions on the users compute= r and send this signed transaction to the third-party for the second signatu= re. This now permits the use of out of band transaction verification techni= ques before the third party signs the transaction and sends to the blockchai= n. >>=20 >> If the third-party is malicious or becomes compromised they would not hav= e the ability to complete transactions as they only have one private key. I= f the third-party disappeared, the user could use the key in cold storage to= sign transactions and send funds to a new wallet. >>=20 >> Thoughts? >> -------------------------------------------------------------------------= ----- >> Dive into the World of Parallel Programming. The Go Parallel Website, >> sponsored by Intel and developed in partnership with Slashdot Media, is y= our >> hub for all things parallel software development, from weekly thought >> leadership blogs to news, videos, case studies, tutorials and more. Take a= >> look and join the conversation now. http://goparallel.sourceforge.net/ >> _______________________________________________ >> Bitcoin-development mailing list >> Bitcoin-development@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/bitcoin-development